1. Field of Invention
The present invention relates generally to the field of exchanging messages using telephone communication systems. More specifically, the present invention relates to sending messages from one telephone to another over a public-switched telephone network.
2. Background of the Invention
Often a person making a telephone call (the xe2x80x9ccalling partyxe2x80x9d) desires to send an arbitrary message to another person (the xe2x80x9ccalled partyxe2x80x9d) that can be displayed to the called party while the called party is using the called party""s telephone or otherwise unavailable to respond to the calling party""s telephone call. For example, in the case of an emergency, it would be advantageous to send a message describing the emergency for display on the called party""s telephone even when the called party is already on the telephone.
Modern pagers allow users to send text messages back and forth to one another. For example, the RIM Inter@ctive pager 950 pager, manufactured by BellSouth of Atlanta, Ga. allows users to compose text messages and send those messages to other users of the pager. However, these pagers do not use the existing public-switched telephone network (xe2x80x9cPSTNxe2x80x9d), nor do they send messages to a telephone. This is disadvantageous in light of the huge number of installed land-line telephones and the increasing proliferation of mobile and cellular telephones, many of which can display text and other digital messages.
Conventional telephone systems provide caller ID data which can be displayed to a called party while the called party is using the called party""s telephone or otherwise unable to answer the calling party""s call. The caller ID data includes the date and time of the telephone call, the calling party""s telephone number and, in some cases, the identity of the calling party. The caller ID data is obtained by a switch on the telephone system, and forwarded to the called party""s telephone for processing and display by a caller ID processor. The caller ID processor can be a device separate from the called party""s telephone, or can be incorporated into the called party""s telephone. The called party""s telephone can be a mobile telephone, a cellular telephone or a land-line telephone.
A schematic diagram of a system for transmitting caller ID data is shown in FIG. 1A. A calling party, using calling party telephone 102, calls a called party at called party telephone 104 over a telephone network 106. Telephone network 106 is generally a PSTN. Switch 108 in telephone network 106 makes a connection between calling party telephone 102 and called party telephone 104. When making the connection, switch 108 rings called party telephone 104. At the end of the first such ring, all or a portion of the caller ID data is displayed on a display screen of a caller ID processor 105 or other caller ID display device, for example, a computer screen.
Switch 108 sends the caller ID information to called party telephone 104 by setting up a protocol for transmitting the caller ID information with called party telephone 104 as follows. Referring to FIG. 1B, after a first ring 210 ends, switch 108 sends a header 205, that identifies the start of the caller ID data. Header 205 advises called party telephone 104 that switch 108 has caller ID data available. If called party telephone 104 can process the caller ID data, for example, using caller ID processor 105, which is attached to, or otherwise incorporated in, called party telephone 104, called party telephone 104 sends a message to switch 108 requesting the caller ID data. In response to this message, switch 108 sends the caller ID data to called party telephone 104 where it is processed and displayed by caller ID processor 105.
Conventionally, the caller ID data includes a PARAMETER LENGTH field, which stores a value indicating the length of the caller ID data in bytes. The end of the caller ID data is established by the value stored in the PARAMETER LENGTH field of the caller ID data. The end of the caller ID data is shown on FIG. 1B as end-of-caller ID 206. Caller ID processor 105 processes the caller ID data until it reaches end-of-caller ID 206, and displays the data in a screen of caller ID processor 105. Generic requirements for switching and signaling for caller ID data processing are described in further detail in Bell Communications Research Inc. (BellCore, now Telcordia Technologies) technical references TR-NWT-000031 and TR-NWT-001188, both of which are hereby incorporated by reference herein in their entirety.
Certain telephones, such as the Nortel Powertouch 350 screen phone manufactured by Nortel Networks of Brampton, Ontario, Canada, allow a user to press a button that causes an announcement to be sent to the calling party indicating that the user has received the call, but is busy and cannot answer it. Further, the announcement can indicate that the called party will get back to the caller as soon as possible. The announcement is not an arbitrary message entered by the called party in response to the specific incoming call. Rather, it is a predetermined announcement that is selected by the telephone manufacturer and played back when the user pushed a particular button on the screen phone.
Disadvantageously, conventional telephones do not provide a capability to send random or arbitrary messages, for example, describing an emergency situation, from the calling party to the called party. Nor does any mechanism exist by which to achieve this desirable result in conventional systems.
The present invention solves the foregoing problems in the art by allowing an arbitrary message to be sent from one telephone to another that is processed and displayed by a message processor that is attached to, or otherwise incorporated in, the receiving party""s telephone. In the preferred embodiment of the present invention, the message processor is a conventional caller ID processor.
In a preferred embodiment of the present invention, a calling party desiring to send a message to a called party inputs an arbitrary message into the calling party""s telephone. The calling party telephone then sends the message to a switch where it is stored in a switch memory. The switch then coordinates with the called party""s telephone to send the message to the called party""s telephone. A MESSAGE LENGTH field is included in the message sent to the switch to indicate to the switch the length of the message.
In the preferred embodiment, the MESSAGE LENGTH is the PARAMETER LENGTH field of conventional caller ID described above, to which the value stored in the MESSAGE LENGTH field is added. After the addition, the value stored in the PARAMETER LENGTH field indicates the number of bytes in the message and caller ID data. In an alternate preferred embodiment, the value of the PARAMETER LENGTH field is set to a fixed length.
Preferably, the message is stored by the switch. The switch subsequently sends the message to the called party""s telephone, specifically a message processor, such as a caller ID processor for display to the called party. The message is displayed on a display device, for example, on the called party""s caller ID processor, even when the called party is already using the called party telephone, or is otherwise unable to answer the calling party""s phone call. In a preferred embodiment of the present invention, the message can be accessed remotely.
In a preferred embodiment of the present invention, the message is input by connecting the calling party telephone to a computer, which is used as the input device. In an alternative preferred embodiment of the present invention, the message is entered using the calling party telephone""s keypad.
Preferably, the conventional telephone system architecture is substantially maintained by the present invention. Thus, the present invention can be easily retrofit into existing telephone networks.
Thus, one object of the present invention is to enable arbitrary messages to be sent from one telephone to another.
Another object of the present invention is to provide an exchange of arbitrary messages between telephones using conventional telephone network architectures.
Another object of the present invention is to provide an exchange of arbitrary messages between conventional telephones without requiring modification of the telephones.
Another object of the present invention is to provide an exchange of arbitrary messages between telephones even when the called party is already using the telephone or otherwise unable to immediately answer the calling party""s telephone call.
Another object of the present invention to allow remote retrieval of stored messages.